Oct 1, 2022 · In this study, sawdust and fresh cow manure were used as composting substrates. Sawdust was collected from a lumber mill in Nanning, Guangxi, fresh cow manure was taken from the dairy farm of Guangxi University, College of Animal Science, and the additive NaHCO 3 was produced in Shanghai Sinopharm Chemical Reagent Co., Ltd., China.